A. Blondel WP 4.7 LAGUNA_LBNO LARG+ND meeting Near detector for CN2PY -- discussion What is needed? What does it take? Ideas…

What is the near detector supposed to do? 0. assure global normalization of the experiment 1.Measure cross-sections for signal   , (CC and NC) e and  e normalization channels as function of neutrino energy Is energy resolution needed is as good as in far detector ? NB We also need the equivalent of NA61/SHINE for that beam are SPY data sufficient? (only 7-10% precision) A. Blondel WP 4.7 LAGUNA_LBNO LARG+ND meeting

Global set up and some numbers Underground (100m), located at 360m from target + possibly underground, (200m deep) 800m from target Event rates are very large. Take 360m location for instance. At 360m location estimate ~2 events per pulse per ton for 750kW and 1 pulse every 6s. 1kton magnetized iron (MINOS ND)  2000 events per pulse if pulse is 10  s long  1 evt / 5ns. Pile-up! Even with scintillator this is not trivial. Resolution for liquid argon in case of pile-up? Detector should not be larger than needed! A. Blondel WP 4.7 LAGUNA_LBNO LARG+ND meeting

HOW LARGE ? Wisdom from calorimeters – for full resolution need 2 I on the sides and 5 I behind the interaction point (assume tails are cought up in MIND) I = 17cm (Iron) ; 80cm (Scintillator) ; 83cm (Larg) (good thing Argon is cheap) Take 1 m 3 of fiducial volume then total mass of detector is typically 70 m 3 of scintillator/Larg. = 70/100 ton 140 events per 10 microsecond pulse is manageable with scintillator Is 200 evts/10microsecond manageable with Larg?

A. Blondel WP 4.7 LAGUNA_LBNO meeting Magnetic detector -- No discussion that the near/far detector concept works very well for the MIND  go for it -- DOES ONE WANTS TO HAVE A MAGNETIZED DETECTOR TO TELL THE CHARGE OF A 4.5 GeV ELECTRON ? If yes, think harder: Liquid Argon 14cm X 0 will require large magnetic field ! $$$ -- Scintillator detector solution: reduce density of plastic generate tracking volume by inserting air gaps or drift chambers orTPCs between layers of scintillator (Variants of the ND280 TPC + FGD concept) -- Position of magnet wrt to this tracking volume (include absorber part or not?) -- is air gap sufficient? What magnetic field? -- need simulation and test beam

1.6m (SC) coil Beam Tracking volume

A. Blondel WP 4.7 LAGUNA_LBNO meeting m (SC) coil Tracking volume B MIND 

A. Blondel WP 4.7 LAGUNA_LBNO meeting An interesting variant would be to have the tracking volume made of a large Gas Argon TPC, surrounded with a solid scintillator absorber. 3m 3 = 5kg (could make it bigger, or at pressure, at cost of surrounding) At 360m location estimate ~2 evts/pulse 750kW and 1 pulse every 6s.  0.01 event per pulse every 6s  events per year Is this enough to tell sign? What is the required number of events? Advantages: -- Upstream target for scintillator cross-sections. -- get cross-sections on Argon -- detailed study of final state stubs (model re-interactions in nucleus) -- a sample of very well measured events -- keep event resolution in time and energy with active volume surrounding it Can we make TPC electronics and field cage transparent enough? AN INTERESTING VARIANT

A. Blondel WP 4.7 LAGUNA_LBNO meeting Some important questions -- do we need to measure the electron neutrino cross-sections ourselves? This will depend on the advent of the muon storage proposal at Fermilab Does this condition the need for magnetic field? -- assume we do. Challenge: For me the relative distance between 360 and 800m does not make enough difference in rate (4.5) to justify two different technologies -- Both rates are probably too large for 100tons of Larg. -- not enough to do the short baseline oscillations either -- solution maybe to embed a gas Argon TPC inside a large volume of fully active scintillator solid (or maybe liquid) followed by a MIND detector, in the near location. -- Conjecture: this, combined with a well designed program of hadroproduction measurements, should be enough.

A. Blondel WP 4.7 LAGUNA_LBNO meeting Near detector for Long base-line experiments What is needed? What does it take? 1- Challenge of precision 2- Near detector vs. far detector: specs for near detector 3- What needs to be done? -- simulations -- detector R&D: a start list and AIDA Program. 4. ancillary experiments

State of the art CNGSno near detector SPY Emulsion (OPERA) LArg (ICARUS) NUMIMag Iron (MINOS ND) TASD (NOvA ND) MINERvA NA49 (+ MIPP) Mag. Iron (MINOS) TASD (NOvA) T2Kon axis : Iron-Scint (INGRID) off axis: ND280 plastic scintillator+TPC NA61 Water Cherenkov Near detector Far detector hadron-prod. measurements will concentrate in the following on detectors with electron capability.

Epiphany06 Alain Blondel near detector constraints for CP violation = A CP  sin 2    solar term… sin  sin (  m 2 12 L/4E) sin   sin   P(   e ) - P(   e ) P(   e ) +P(   e ) Near detector gives  and  diff. cross-section*detection-eff *flux and ibid for bkg BUT: need to know also e, e diff. cross-section* detection-eff with small (relative) systematic errors.  knowledge of cross-sections (relative to each-other) required  knowledge of flux! interchange role of e and  for superbeam Superbeam:

Epiphany06 Alain Blondel maximum T asymmetry for sin  = ! asymmetry is a few % and requires excellent flux normalization (neutrino fact., beta beam or off axis beam with not-too- near near detector ) NOTES: 1. sensitivity is more or less independent of  13 down to max. asymmetry point 2. This is at first maximum! Sensitivity at low values of  13 is better for short baselines, sensitivity at large values of  13 is better for longer baselines (2d max or 3d max.) 3.sign of asymmetry changes with max. number. statistical error Asymmetry 2011 S. Parke at NUFACT11

Epiphany06 Alain Blondel near detector constraints for CP violation = -A CP  - sin 2    solar term… sin  sin (  m 2 12 L/4E) sin   sin   P( e   ) - P( e   ) P( e   ) + P( e   ) Near detector gives e diff. cross-section*detection-eff *flux and ibid for bkg BUT: need to know  and  diff. cross-section* detection-eff with small (relative) systematic errors.  knowledge of cross-sections (relative to each-other) required  knowledge of flux! interchange role of e and  for superbeam beta-beam or nufact:

A. Blondel WP 4.7 LAGUNA_LBNO meeting Challenge of precision -- if sin 2 2  13 is very small : challenge is --- signal statistics --- background level and subtraction -- if sin 2 2  13 is large: challenge is signal systematics Asymmetry is at most 25% and 5% systematics on each of neutrino and antineutrino leads to a)signal cross-section systematics (including selection cuts!) b)near-far flux systematics c)systematic errors e.g. coming from uncertainty in matter effect. P(   e ) - P(   e ) P(   e ) +P(   e )  signal,far ( e )/  signal,near (  )   A CP = 2   signal,far ( e )/  signal,near (  )

A. Blondel WP 4.7 LAGUNA_LBNO meeting CP asymmetry decreases as Systematics! sin 2 2  13 increases… Systematics! Challenge of precision! Flux and cross-sections must be known to <<5%  hadro production experiments + near detectors  cross-sections to 5% if needed to measure cross-sections to 1% precision  mini neutrino factory (first step muon storage ring) TASD, LArg…

Near detector specifications consider here near detector in two functions: -- provide normalisation of experiment -- provide cross-section measurements that are necessary for -- background subtraction -- interpretation of experiment in terms of oscillation probabilities requirements for near detector: -- must be as good or better than far detector (not as easy as it sounds, because the far detector is huge and provides excellent event containement) -- must be located so as to allow good near/far extrapolation (not too close) -- must allow precise measurements of cross-sections (well defined fiducial mass can chemical composition) -- do we need magnetic detector? -- do we need a program of test beam measurements? -- is detector location critical? (distance to beam, alignment to far detector?) -- detector chemical composition?

A. Blondel WP 4.7 LAGUNA_LBNO meeting

containment issue Is particularly relevant for the case of the 1 st vs 2 d maximum technique: the 2d maximum is quite narrow and energy resolution is critical. need about  2 interaction length transversally and +5 interaction length deep around the fiducial volume I = 17cm (pure iron) 80cm (plastic) 83cm (LArg) this is well verified for MINOS ND, less well but almost for NOVA ND not at all for T2K ND280. need simulation or test beam to assert this number

A. Blondel WP 4.7 LAGUNA_LBNO meeting Neutrino Factory detectors Neutrino detector: Magnetised Iron Neutrino Detector (MIND): iron+scintillator Multi Pixel Photon Counter (MPPC) kt MIND Scintillator +WLS fibre Toroidal B-field: T 14 m

A. Blondel WP 4.7 LAGUNA_LBNO meeting Stopping properties of pions and muons in Minerva-like detector This will be studied in the MICE EMR at RAL using stopping e/mu/pi of both signs For LArg/LENA could also be tested at RAL (there exist a EUCARD TNA for that) -- Charge separation for electrons in magnetic field (TASD, LArg) This can be studied in the MORPURGO magnet at CERN -- Muon Charge separation in MIND-like detector This can be studied in a baby-MIND detector at CERN --hadronic shower angular and transverse momentum resolution in TASD and MIND or LArg or LENA (tau detection in superbeam or high energy neutrino factory) this requires about 2m deep MIND (that is CDHS shower box) and 5m deep (?) TASD or LArg in hadron test beam e.g. at CERN or Fermilab -- How many interaction lengths are needed? Physics issues needing test beam input (from ISS report) 200 MeV/c e/mu/pi beam at RAL

A. Blondel WP 4.7 LAGUNA_LBNO meeting Fast detectors for magnetized near detectors in Superbeam, beta-beam, neutrino factory Accurate position resolution (mm)  triangular shaped scintillator bars Magnetic field  si-PMT readout MICE calorimeter = 1m 3 Next step: test at CERN in Dipole magnet in H8  1.6m diameter. Variable density by spacing planes -- reconstruction of showering electrons -- stopping properties of pions and muons First test in T9 beam at CERN – position resolution few mm

A. Blondel WP 4.7 LAGUNA_LBNO meeting M. Prest AIDA meeting 3/5/2011

A. Blondel WP 4.7 LAGUNA_LBNO meeting

Neutrino activities within AIDA WP8 Task 8.2.1: –Develop test beam area in H8 beamline (North Area at CERN) –A study of the upgrade of the H8 beam to deliver low energy electrons, muons and hadrons for neutrino experiment prototypes Task 8.5.2: –Build a Magnetised Iron Neutrino Detector (MIND) prototype –Install a Totally Active Scintillating Detector prototype inside the Morpurgo magnet –This will allow to test both electron and muon charge ID in the same test beam –Apart from the equipment, detectors and electronics we would also need a DAQ (would the common DAQ be suitable?) –MIND prototype becomes a facility for other users in the test beam

A. Blondel WP 4.7 LAGUNA_LBNO meeting Milestones and deliverables Task 8.2.1: design study for low energy particle beam line –MS27: Specifications for beam line fixed (month 12) –D8.3: Design study on low energy beam line: Design and implementation study on a low energy beam to the range of 1 (or possibly less) and 10 GeV (month 26) Task 8.5.2: TASD and MIND –MS28: Design of TASD and MIND (month 26) –MS36: Installation of TASD and MIND (month 33) –D8.11: Infrastructure performance and utilization - TASD and MIND are constructed and tested for their performance. (Will there be test beams in 2014?)

A. Blondel WP 4.7 LAGUNA_LBNO meeting Questions and TASKS 1.Low energy option: (to the Frejus Afficionados) expect this to be a Water Cherenkov far detector and expect near detector to be absolutely crucial. -- where can the near detector be located in the design? -- can this be a water Cherenkov? How far can it be located to stand the rate? or can this be a plastic scintillator with water targets as in ND280? -- do we need magnetization? -- how/where can one make the necessary hadroproduction experiment? -- what test beam activity would be useful? NB I have my own guesses to these but need your answers! We would like to have a couple volunteers from the CERN to Frejus project

A. Blondel WP 4.7 LAGUNA_LBNO meeting Questions and TASKS 2 High energy project (Pyhasalmi afficionados) Expect this to be -- LArg + MIND -- LENA (Liq Scintillator) -- MIND or TASD+MIND -- where can the near detector be located in the design? -- can this be a LArg? A Liq. Scint.? How far can it be located to stand the rate? -- can this be a plastic scintillator as in ND280? -- hadronic/neutron shower containment? -- better ideas (pressurized LArg TPC)? -- do we need magnetization? -- how/where can one make the necessary hadroproduction experiment? -- what test beam activity would be useful? We would like to have a couple volunteers from the CERN to Pyhasalmi project

A. Blondel WP 4.7 LAGUNA_LBNO meeting Conclusions -- near detector is at heart of control of systematics in LBNO experiments -- requirements for ND in short and long baseline versions of LAGUNA will be different -- would like to have a few volunteers from both options to start concepts of near detectors -- conceptual thinking -- simulations -- articulate test beam requirements and ancillary measurements THANK YOU!